The day batch 64 entered the bloodstream

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A crisis meeting at Parkville in May 1962 was convened
following findings that the latest batch of polio vaccine was
contaminated with a newly discovered virus. Gary Hughes
reports.

The eight scientists gathered in the meeting room at the
Commonwealth Serum Laboratories in Parkville included the key
researchers who had helped turn the tide in the fight against polio
in Australia.

But the mood was far from celebratory as the meeting got under
way on May 1, 1962.

The team responsible for developing and producing the local
version of the Salk polio vaccine in 1956, which had been given to
millions of Australians during the following years, was facing a
crisis.

Four days earlier CSL biochemist John Withell had completed
laboratory tests that confirmed what had been feared: the latest
batch of polio vaccine was contaminated with a newly discovered
virus that came from infected monkey kidneys used to produce
it.

The virus had been designated SV40 - the SV stood for simian
virus - because it was the 40th such virus that had been
identified. But this virus, discovered by British researchers the
previous year, was different. Tests in the US had shown it could
cause aggressive cancers in hamsters and the virus was not killed
in the normal process used to manufacture polio vaccine.

In the words of John Withell, who went on to become head of the
government's Therapeutic Goods Administration laboratories in
Canberra, SV40 "was recognised straight away as a fairly nasty
virus".

Now those at the meeting, which, according to the minutes in the
National Archives, were called together to discuss "SV40 and other
aspects of the polio vaccine production", were confronted with the
dilemma of what to do next.

The discovery of SV40 contamination could not have come at a
worse time for the government-run CSL. The laboratories, which
conducted virtually all vaccine research and production in
Australia, had just undergone one of the most turbulent periods in
its history, with mounting political pressure over delays in
producing polio vaccine, the removal of its director, management
upheavals and cost blow-outs.

While the introduction of the Salk vaccine in Australia in 1956
had blunted the threat of polio, outbreaks had continued.

The spectre of poliomyelitis, which could lead to death or
permanent paralysis, was still enough to cause widespread public
panic. By 1962 Australia had suffered and estimated 30,000 cases of
paralytic polio.

Public hysteria - cinemas were shut and in some cases babies
banned from public transport - had turned up the pressure on
politicians and health authorities.

In 1961 state health authorities and health ministers were
pressing Canberra to provide increased amounts of polio vaccine
amid a growing shortage caused by production problems at CSL. Two
batches of vaccine, representing about 1.4 million individual
doses, had been destroyed in November 1961 because they had failed
safety tests.

The release of other batches was delayed because independent
tests by Fairfield Hospital showed the vaccine still contained live
polio virus, forcing it to be reprocessed.

Even before the discovery of SV40 the pressure was starting to
show among senior staff, according to CSL documents, with some
expressing concerns at the way standards were being
compromised.

In September 1961 batch 58 was issued despite a written warning
from CSL's senior medical consultant that "it does not meet CSL's
accepted standards in potency and is a long way short of the
increased potency approved by the National Health and Medical
Research Council".

In August 1961 senior researcher John Graydon wrote a memo
expressing concern that important decisions on the release of
vaccine batches that failed safety tests were being influenced by
the supply situation. Effectiveness and safety, he said "should be
the determining criteria".

The shortages, production problems and the continuing demand -
by 1961 less than half the population had been vaccinated - had
even led authorities to secretly buy vaccine from overseas.

Now SV40 posed a new threat to production, which in turn would
spark more public embarrassment for CSL and federal health
authorities.

CSL was no stranger to the lurking simian viruses, which
contaminated vaccines through the infected kidneys of monkeys
imported from Asia by the hundreds.

The manufacturing process involved the pulping of monkey kidneys
to make cell cultures in which the polio virus was grown before
being inactivated and turned into vaccine.

CSL's production records in the National Archives show the
presence of a simian virus disrupted safety tests of finished
vaccine in 1957. In 1958 a batch of finished vaccine was destroyed
after a live "non-polio virus" was detected. That same year a virus
"consistent with it being a simian virus" was found in another
batch.

Simian viruses, along with other factors such as stress, were
also causing CSL's imported monkeys to "die like flies" at
Melbourne Zoo where they were kept, according to Withell.

In May 1961 CSL's director, Val Bazeley, had written to the
director-general of health partly blaming continuing shortages of
polio vaccine on the deaths of monkeys from a simian virus and the
fact that the virus was getting into batches of vaccine.

A few months later Bazeley, who had worked with Salk in the US
and brought seed virus back to Australia in 1955 to start local
polio vaccine production, would be gone from the director's chair
after a row with Canberra bureaucrats.

CSL scientists were first warned about SV40 contamination of
Salk polio vaccine and its potential threat in April 1961 by the US
Department of Health, after the monkey virus had been found to have
survived the process used to inactivate live polio viruses used
during US vaccine production.

US authorities said they had found SV40 in half of the samples
it had tested from its own vaccines and urged other manufacturers
around the world that "every effort should be made to institute a
program of testing each lot of vaccine to ensure that vaccine
reaching the market is free of simian agents". The Americans also
adopted the policy of not releasing any new batches of vaccine
until it had been shown to be free of SV40.

CSL received a first-hand account of the problem in November
1961 when one of its most senior researchers, Allan Duxbury,
visited America's Biological Standards Laboratory.

In a three-page report sent back to Melbourne, Duxbury said the
"most interesting" part of his visit was the study of SV40 and the
fact it had been shown to cause malignant tumours in hamsters
"unlike any previously produced by other viruses". But according to
CSL records the first testing of local vaccines did not start until
February 1962.

Now a decision had to be made by CSL's new director, Ron
Greville, on how to cope with this new threat and further potential
embarrassment.

According to the minutes of the meeting, "Dr Greville opened the
discussion by stating that although SV40 virus was present in batch
64, the batch would be issued; a decision which was founded on the
belief that probably much vaccine in the past was probably
similarly contaminated".

One of those working on polio vaccine production at CSL at the
time was Alan Hampson, now the deputy director of the World Health
Organisation centre for influenza research, based at CSL.

"I would not be at liberty to discuss what might have been found
in vaccines issued by CSL," he told The Age.

The man who found SV40 in CSL's vaccines, John Withell, reviewed
his original research workbooks for The Age after they were located
in the National Archives.

Withell, 72, who is now retired and living in Canberra, was
surprised at how few samples of previously released batches of
polio vaccine were available for testing for SV40. Records show
that the samples retained for safety testing were frequently
combined to produce new batches of vaccine to overcome
shortages.

Withell's original workbooks show he conducted tests on three
earlier batches to batch 64: number 49, which was released in
October 1959, number 58 released in September 1961 and number 63
released in February 1962. The test results show SV40 was found in
batches 49 and 63. He also found the virus in vaccine batch 65,
which was released in October 1962, and batch 66.

Each batch of vaccine represented about 700,000 individual doses
of Salk vaccine. Withell said it was likely that other batches of
vaccine produced before 1962, which were not available for testing,
were also contaminated.

It was not until batch 66 that, on instructions from federal
health authorities, CSL treated the vaccine to kill the living SV40
virus it contained. The process, however, also destroyed the
effectiveness of the vaccine and it had to be thrown away.

Withell also tested the "seed" polio viruses used to make each
batch of vaccine. The vaccines contained three kinds of polio
viruses, which were killed using formaldehyde to provide immunity.
The type two polio seed virus was "stuffed full" of SV40, Withell
told The Age. Although the other two types of polio virus were
negative, the effectiveness of the testing method cast doubt on
those results.

Withell has also told - for the first time - how he did
experiments for CSL in an attempt to establish whether SV40 could
cause cancer in humans. He and another researcher infected cells
taken from human embryos with the monkey virus and recorded how the
cells were "transformed", or became cancerous.

But the results of the research, done in late 1962 while the
contaminated doses of vaccine batch 64 were being prepared for
release, were never made public.

Withell said he handed the results to a committee overseeing
research within CSL, and heard nothing more.

Not everyone at CSL was in favour of releasing polio vaccine
contaminated with SV40.

Withell and a number of other younger scientists were not only
concerned at the cancer threat the living monkey virus posed, but
also with the risks from vaccine where SV40 had been killed.

The young scientists were fearful that DNA from the killed SV40
virus could trigger cancers. Some 35 years later their fears began
to appear well founded when SV40 DNA began turning up in human
cancers.

Withell said there was heated debate within a CSL advisory
committee set up at the time to examine the issue.

"I was strongly of the opinion that it shouldn't be released,
because even if the SV40 had been killed, it still had the SV40
DNA. There were concerns that DNA might be sufficient to have a
carcinogenic effect in the recipient of the vaccine.

"We actually had a vote on that and I proposed we shouldn't.
That was carried, but I was never quite clear what happened to the
batches involved. As far as I can tell, that virus committee never
met again. I was always amused about that. I left (CSL) shortly
after that."